RESUMO
The absolute response of the GE Amersham Typhoontm imaging plate scanner is studied in this paper. The sensitivity function of the scanner with different photomultiplier tube voltages was obtained by using a pre-calibrated Cu Kα x-ray tube. The results showed that the sensitivity function decreases exponentially with higher voltage and is also affected by the scanning pixel size. The spatial resolution and the fading effect of the imaging plate system on x rays were also investigated and compared with the previous scanner models.
RESUMO
A multi-channel Thomson parabola spectrometer was designed and employed to diagnose ion beams driven by intense laser pulses. Angular-resolved energy spectra for different ion species can be measured in a single shot. It contains parallel dipole magnets and wedged electrodes to fit ion dispersion of different charge-to-mass ratios. The diameter and separation of the entrance pinhole channels were designed properly to provide sufficient resolution and avoid overlapping of dispersed ion beams. To obtain a precise energy spectral resolving, three-dimensional distributions of the electric and magnetic fields were simulated. Experimental measurement of energy-dependent angular distributions of target normal sheath accelerated protons and deuterons was demonstrated. This novel compact design provides a comprehensive characterization for ion beams.
RESUMO
Angular distribution of protons is measured from ethanol droplet spray irradiated by linearly polarized 150 fs laser pulses at an intensity of 1.1 x 10(16)W/cm2. Fast protons (with energies >16 keV ) with an anisotropic distribution can be observed only in or near the polarization plane of the laser fields, while the slow protons (with energies